Digester.



Patented Sept. 25, I900.

a W A 6 B E. G. MURPHY.

D l E E S T E 8.

(Application Mad Jan. 22, 1900.)

No Model.)

WITNESSES THE wonnfs PETERS co. PNoTouT'HQ, WhSHINGYOPL n. c.

Nrrn TATES I ATENT FFICE.

EDGAR GUILLOW MURPHY, OF SANDY HILL, NEW YORK.

DIG ESTER.

SPECIFICATION forming part of Letters Patent No. 658,572, datedSeptember25, 1900.

pplication filed January 22,1900. Serial No. 2,389. No modeL) To allwhom it may concern:

Be it known that I, EDGAR GUILLow MUR- PHY, a citizen of the UnitedStates, and a resident of Sandy Hill, in the county of Washington andState of New York, have invented a new and Improved Digester, of whichthe following is a full, clear, and exact description.

The purpose of this invention is to construct a cement-lined digesterthe lining of which will not be influencedthat is to say, cracked andbrokenby the contract-ion and expansion of the digester-shell due to thealternate heating and cooling thereof.

This specification is the disclosure of one form of my invention, whilethe claims define the actual scope thereof.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the views.

Figure l'is a view of the digester with parts broken away on the line 11 of Fig. 2. Fig. 2 is a section on the line2 2 of Fig.1, and Fig. 3 isan enlarged detail section taken horizontally through one of the seamsof the digester.

The digester-shell a is constructed in the usual manner-that is to say,of a number of sections of sheet metal fastened together to form thecomplete shell. These sections have their meeting edges sealed to formthe seams by means of exterior butt-straps b and interiorinwardly-arched straps c, the three parts a, b, and 0 being rivetedtogether, as shown. The arched butt-straps c extend inwardly to inclosethe space surrounding the seam, and thus the seam is protected fromtheaction of the contents of the digester, which tend in many cases todestroy the calking of the seam. The shell is now lined with cement, asindicated at d, the cement being laid directly against the inner wallsof the shell and extending to the sides of the arched portions of theinterior butt-straps 0, such straps serving to break the continuity ofthe cement lining, which, as shown best in Fig. 3, is of a thicknessless than the height of the arched portions of the straps c. The resultof this is that the cement is not placed in the shell in the form of acontinuous and unbroken layer, but is divided into a number of separatepieces which are independent of each other. With this arrangementcontraction and expansion of the metallic shell will not tend tofracture the cement and destroy the lining. Inward of the cement one ormore layers of brick eare placed, as shown, such brick completelycovering the buttstraps c, as shown.

I am aware that previous to my invention digesters have been constructedwith cement linings; but these linings are invariably in the form of anunbroken layer of cement extendin continuously throughout the interiorof the aigester, and such linings are known to be disadvantageous inthat the expansion and contraction of the digester-shell readilyfracture the cement and destroy the lining. The essential feature of myinvention is therefore building the shell with the buttstraps 0 havinginwardly-projected portions, at the sides of which the cement lining isplaced in separate and independent sections, the butt-straps operforming the double function of protecting the seam in the shell andof breaking the continuity of the cement.

Having thus described my invention, I claim as new and desire to secureby Letters Patent-- 1. A digester, the shell of which is constructed ofa section or sections of sheet metal, meeting edges of which areprovided with an interior butt-strap, a portion of which is arched orbowed inward away from the same, to protect the seam, and a cementlining for the digester, the same being placed in separate andindependent masses at the sides of the arched or bowed portions of thesaid butt-strap, such portions of the buttstrap projecting completelythrough the ocment, to break the continuity thereof.

2. A digester, the shell of which is constructed of a metallic plate orplates, meeting edges of which are joined by a butt strap or straps,portions of which are projected inward from the shell, and acementlining laid against the shell, the said inwardly-projected portions ofthe butt strap or straps passing completely through the lining, thebuttstraps serving to protect the seam in the digester-shell and also tobreak the continuity of the cement, which is thus formed into a numberof separate and independent masses.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EDGAR GUILLOW MURPHY.

Witnesses:

GUY R. CLARK, FRED. E. EARLE.

